Method of and mechanism for operating a drying apparatus



Dec.1 0,1940 HER 2.224,608

METHOD OF AND MECHANISM FOR OPERATING A DRYING APPARATUS Filed Nov. 2, 1937 LJLJ I 7 Jami?- a WM 'M fzma Patented Dec. 10, 1946 METHOT) OR AND MECHANISM FOR OPERAT- INGA DRYING APPARATUS Lucien Pierce, Malden, Mass, assignor to The American ,Laun

dry Machinery Company, Cincinnati, Ohio, a corporation of Ohio Application November 2, 1937, Serial No. 172,415

9 Claims.

.10 sure is introduced tangentially into the cham ber, preferably at its-bottom, so that the clothes are swept around the chamber and tumbled as they are being dried, the air escaping through a foraminous portion of the chamber wall near the top thereof.

In the operation of driers of this type, difflculty has been experienced by a tendency on the part of the contents of the chamber to flatten against a wall thereof instead of tumbling go in the -air stream. For example, a light piece of cloth may fly againstthe foraminous outlet and be held there, blocking the exit of the air. Furthermore, the air stream may not be strong enough to lift a batch of heavy articles such as wet bath towels, blankets and the like. In order to overcome these dimculties, suitable mechanism is provided according to the present invention to vary the intensity of the air stream at predetermined intervals. More specifically, 39 the air stream may be periodically reduced in velocity or cut oil altogether. This causes any portion of the contents of the chamber which may be clinging to the wall of the chamber to drop to the bottom of the chamber where it can be picked up by the air stream the normal velocity of which is resumed after every brief interval. Such reduction or cutting of! of the air stream can be supplemented by occasional brief increases in the velocity of the stream so m as to lift and put in motion the contents of the chamber when too heavy to be raised by the I normal air stream. According to the invention,

the gate which controls the stream of air entering the chamber is automatically operated by 5 suitable driven mechanism so that the gate is periodically closed for brief periods, such periods being spaced by considerable intervals of time so that the effective drying operation of the machine will not be materially diminished. Drying machines of the tumbling type, particularly for use in laundries, are often constructed with a pair of chambers to which streams of air are supplied from a common source. According to the invention, control 55 mechanism is provided to operate the'gates for the two chambers in such a manner that the gates will be operated in alternation to shut and reopen. During the brief periods in which either gate is closed, the air supply from the common source will be directed to the other chamber a only so that air will enter this chamber at a materially increased velocity. Thus in the operation of a machine having two chambers, the velocity of. the air stream will be periodically altered, being alternately increased and diminished or cut ofl altogether. Suitable appara tus may be provided as desired for actuating the gates in the manner described. Such apparatus is hereinafter described and is illustrated on the drawing of which 1 Figure 1 is a front elevation of a drying machine of the tumbling type, including apparatus embodying the invention.

Figure 2 is a side elevational view of the operating device and a cross sectional view of the drying machine on a front to rear vertical plane;

Figure 3 is a section on the line 3-3 of Eigure' 1. v a V Figure 4 is a section on the line 4-4 joi iilg: ure 1, showing in dotted lines the different :posi- :5 tions of the lever arm during the movement of the operating device and .also showingin'dotted lines the position of the notch' in or i'e ofthe cam disks when the follower is .moved into the Y notch of the other cam disk.. e

As illustrated lnFigure 2,, a-"drying machine of the tumbling type may comprise a housing l0 within which is a cylindrical chamber l2 adapted to receive the clothes or otherfarticles to be-dried. The clothes are inserted through 35 a front opening which is normally closed by a sliding gate i4. At the bottom of the chamber I2 is an opening l6 through which a stream of air may be introduced tangentially into the chamber whirling around in the chamber about a horizontal axis and being exhausted through perforations l8 into a chamber 20 within the casing III. Part of this air is exhausted through a discharge vent 22, the remainder being circulated around a bafile plate 24 into a chamber 26 where it may pass through a heated radiator 28 for recirculation. )To this recirculated air is added a stream of fresh air entering through a grid 30 in the casing Hi. This air mixes with the recirculated air and is impelled by a centrlfugal air pump 32 through the entrance l6 into the chamber 12. As indicated in Figure 1, the drying machine is made with two chambers l2 arranged coaxially, each chamber having its individual door or gate ll for the admission of as vIf the rod 44 is pulled forward, the corresponding gate opens, but, if it is pushed toward the rear, the gate 40 may be partly or fully closed so as to reduce or cut of! the stream of air entering the chamber I! through the port ll.

It is evident that various mechanical devices can readily be constructed to operate the rod 44 and the gate 48. An illustrative device is shown on the drawing and comprises a lever arm which is pivoted at 52, the lower end of the arm being connected to the outer end of the rod 44. This connection is preferably made in such a manner that the arm can readily be disconnected from the rod 44 for manual operation of the latter. The arm 58 is provided with a cam follower 54 which rides on the edge 58 of the disk cam 58. This cam is circular in contour except for a notch 80. As shown, the cam is mounted on a shaft 82 which is rotated stepby-step by means of a pawl 84 which engages in the teeth of a circular ratchet I mounted on the shaft 82. The pawl 88 isattached to an arm 68 pivoted at HI. At the end of the arm 88 is a cam follower 12 which is held against the edge of an eccentric disk I4 by a spring 16. The eccentric H is mounted on a shaft 80 on which is also mounted a worm gear wheel 82 meshing with a worm 8| on a shaft 86 which is driven by a suitable motor 88. As indicated in Figure 1, the cam disks '8 for both of the chambers It may be mounted on the shaft 82, these disks being preferably arranged so that their notches to reach the respective cam followers 54 at different times as indicated in Figs. 1 and '4 and by full and dotted lines in Fig. 4. Thus the gates 48 controlling the air streams to the two chambers I! are never operated simultaneously.

The motor 90 is preferably driven at a constant speed so that thegear wheel 82 rotates at a slower but constant speed and the arm 68 rocks at regular intervals. Each rocking movement of the arm 68 toward the left advances the ratchet wheel 66 one tooth, this advance being sufficient to cause the cam follower 54 to ride from the position shown in Figure 3 to the position shown in Figure 4. This results in a partial or complete closing of the corresponding gate 40, according to the depth of the notch 60 in the cam disk 58. The next rocking movement of the arm 68 toward the left causes the cam follower 54 to ride out of the notch 60. Thus the gate 40 is closed for only a brief period, be-' briefly closed, increasing momentarily the stream of air entering the first chamber. For instance, as shown in the drawing, the ratchet wheels 66 have twenty-eight teeth. Assuming that the ratchet wheel 66 makes one revolution every five minutes, each of the gates 40 willbe alternately closed for approximately ten seconds during that period. The reduction or cutting 01! of the air supply by one of the-gates permits garments which may be clinging to the outlet of the chamber, the air supply of which is controlled by that gate, to drop to the bottom where they may be picked up when the air stream resumes normal velocity. The periodical surges or increases in the air stream in the other chamber caused by the closing of the gate in the companion chamber serve to dislodge clothes or other articles which may be too heavy or wet to be raised initially by the normal air stream.

It is evident that by using cam disks 58 with only one notch 60 in each disk, the brief periods of alteration of velocity of the air streams will be followed by very much longer intervals of time in which the air flow to both of the chambers is normal. If desired, the cam members 58 may be made with more notches arranged as desired. The closing movement of the gates 40 may be under the influence of gravity, or, if desired, springs 82 may be provided to ensure proper closing movement of these gates. If two or more drying machines are set side by side, a single cam shaft 62 may extend past all of the machines to carry all of the cams 58 for these machines. Other alternative features and details of construction such, for example, as the use of channel cams instead of the edge cams shown, may be employed, and alterations and modifications may be made in the apparatus illustratedwithout departing from the spirit or scope of the invention defined in the following claims.

I claim:

1. In a drying machine having an approximately cylindrical chamber, means for blowing a stream of air tangentially into the chamber to tumble clothes or the like which have been inserted therein-to be dried, and a gate for controlling said air stream: a device for closing and promptly reopening said gate, means for operating said device at predetermined intervals, and means for driving said operating means.

2. In a drying machine having a pair of approximately cylindrical chambers, a common means for supplying air under pressure, means for directing a stream of air tangentially into each said chamber from said common supply means, and a gate for each said stream operable to control the flow of each stream into the corresponding chamber; operating means for each gate to close and promptly reopen the gate, and means for actuating said operating means alternately at predetermined intervals.

3. A drying machine having an approximately cylindrical chamber for the fabric, means for introducing a stream of air substantially tangentially into the lower portion of said chamber to tumble fabric therein, means for controlling said air stream, a device for regulating said controlling means to increase or lessen the intensity of the air stream at periodic intervals, and power means for operating said device.

4. A drying machine having an approximately cylindrical chamber for the fabric, means for blowing a stream of air substantially tangentially into the lower portion of said chamber to tumble fabric therein. means for controlling said air stream, a device for at least partially closing said air stream to lessen the velocity of the air at periodic intervals, and power means for operating said device.

5. A drying machine having at least two approximately cylindrical chambers, common means for supplying air under pressure to both of said chambers, and means for controlling the flow of air into each of said chambers, a device associated with each chamber for regulating the intensity of the air stream into each chamber at periodic intervals, and power means for operating said devices to lessen the flow of air into one of said chambers and simultaneously increase the flow of air into the other chamber at periodic intervals.,

6. A drying machine having a casing formed to provide a plurality of substantially cylindrical drying chambers, each having a perforated wall portion, air moving means communicating with each of said chambers, shutoff valve means between the air moving means and each chamber, and means arranged to close the valve means of said chambers intermittently and in order for such short periods during a drying cycle to prevent articles lodged against said perforated wall to fall away therefrom, and to periodically increase for such short periods the velocity of the air stream flowing into each chamber during the drying cycle to cause tumbling of heavy fabric therein.

7. The method of drying fabric which comprises placing the moist fabric into an approximately cylindrical chamber having outlet openings in its upper portion and an opening leading into its lower portion, introducing a stream of air into said chamberthrough the lower opening, and periodically altering the velocity of the air stream for brief periods during the drying operation.

8. The method of drying fabric which comprises placing the moist fabric into an approximately cylindrical chamber having outlet openings at its upper portion and an opening leading into its lower portion, introducing a stream of air into said chamber through the lower opening to tumble the fabric while it is being dried, and periodically decreasing the velocity of the air stream during the drying operation to permit fabric obstructing the outlet openings to fall to the bottom of the container.

9. The method of drying fabric which comprises placing a portion of the fabric into each of two approximately cylindrical chambers each having an outlet opening at its upper portion and an opening leading into its lower portion introducing a stream of air into each of said chambers through its lower opening to tumble the fabric therein while it is being dried, and peri'odically decreasing the velocity of the air stream flowing into one of said chambers while simultaneously increasing the velocity of the air stream flowing into' the other chamber during the drying operation, whereby light fabric obstructing the outflow of air in one chamber is permitted to fall to the bottom of this chamber, while the increased velocity of the air flowing into the other chamber tumbles heavy fabric.

LUCIEN PIERCE. 

